Bioassay-directed identification of toxicants in an acetonic extract of a sediment of the riverine Spittelwasser in the industrial region of Bitterfeld (Germany) was conducted. For this purpose, a combination of chromatographical fractionation, chemical analysis, and a biotest battery including Vibrio fischeri (inhibition of bioluminescence), Daphnia magna (immobilization), and Scenedesmus vacuolatus (inhibition of cell multiplication) was applied. Major toxicants identified and confirmed were methyl parathion (D. magna), prometryn, N-phenyl-beta-naphthalene amine, PAHs (S. vacuolatus), and tributyltin (all biotests). Toxicity to V. fischeri was dominated by elemental sulfur. Results indicate high toxicant loads in the sediment about 7 years after closedown of a majority of chemical production sites at Bitterfeld. Comparison of potential exposure and toxicity data indicate a severe hazard potential to aquatic organisms due to organic toxicants. The results illustrate the potency of a biotest battery for identification of toxicants in contaminated sediment within the frame of toxicity identification procedures.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p164.html

A complete life-cycle test with zebrafish was carried outwith different concentrations of the binary mixture 3,4-dichloroaniline andlindane under flow-through conditions. Length and weight of fish of theF1-generation were reduced, even in the lowest test concentrationof 2 microg/L 3,4-dichloroaniline and 40 microg/L lindane. The same effects werefound in the early life stage test for the F2-generation. In themixture of 100 microg/L 3,4-dichloroaniline and 40 microg/L lindane, fish whichwere exposed for their whole life time stopped spawning, irreversibly; thefish population will become extinct. In an additional experiment, fish wereexposed to the same xenobiotic concentrations after reaching maturity. Inthis case, egg production was reduced. Cessation of egg production occurs ina concentration of 200 microg/L 3,4-dichloroaniline and 40 microg/L lindane.Nevertheless, effects on spawning are influenced by duration of exposure andthe life stages of exposure.

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